


Alien and the Beast

by Torikour



Category: Invader Zim
Genre: Alien Biology, Bottom Zim (Invader Zim), Eventual Romance, Eventual Sex, Eventual Smut, Irken biology, M/M, Mothman, Mothman Dib, Porn With Plot, Smut, Top Dib (Invader Zim), zussy
Language: English
Status: In-Progress
Published: 2020-10-30
Updated: 2020-10-30
Packaged: 2021-03-09 01:55:21
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 5,478
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27286771
Author URL: https://archiveofourown.org/users/Torikour/pseuds/Torikour
Summary: Dib’s hunt for paranormal creatures goes horribly wrong, resulting in him becoming the very creature he had been going after.He has trouble staying in control especially with his anger issues and his new found condition- being mothman.Not wanting to hurt his family and people at Hi Skool, he isolates himself deep in the forest in an abandoned mansion.Zim wonders where his arch nemesis has gone, and begins his search.. but what will he do when he finds out his Dib is quite literally now a beast?
Relationships: Dib & Zim (Invader Zim), Dib/Zim (Invader Zim)
Comments: 12
Kudos: 91





	Alien and the Beast

Dib hastily gets his dark red boots on and grabs his swollen eyeball brief case- finally taking the first step in to solving the biggest mystery he had been wanting to solve. He fixes his glasses, throws on his black lab coat on before running down the stairs and up to the front door. 

“I would ask where you’re going in the middle of the night but I think I already know.” Gaz grumbled from the couch, sitting back and playing her game in her pyjamas. 

“I’m not going to Zim’s place this time Gaz- I’m going back to the forest!” He responded, sounding excited. 

“Whatever, just don’t destroy the car this time. I need it tomorrow to pick up a game.” She said without looking up from her game per usual. 

“I won’t Gaz! Don’t worry. I’ll try and be back around 2am!” He said as he grabbed the keys on the key hanger, swung open the front door and headed out for the night. 

Dib hurried his way to the black car, unlocking the door and throwing his brief case in the empty passenger seat. He sat behind the wheel, slamming the door shut and then began his drive to the forest.

————————————-

It was one hour later that he arrived at his destination, parking the car crookedly in the empty parking lot. He pulls out his phone, checking the map he had downloaded before hand since he knew he would get no connection in the forest. 

“..Don’t worry mom. I’ll solve this mystery..” He mumbled as he looked at the map, checking the suspected area before starting his journey in the dark.  
Today marks the 15th year since his mother’s death- or as some may say, disappearance. Nobody saw her die, nobody found her body and Dib was determined to find out what the hell happened. The last time he ever saw her was at age 3, when he was clueless and unfortunately remembers almost nothing. 

It wasn’t until he turned 18 that his father decided to open up about her past, and finally gave Dib access to her belongings and case files of her whereabouts. 

-Flashback-

“Dad, please.. I’m an adult now. Whatever you have to say about mom I can handle it!” Dib followed his dad into the kitchen, who was seeming to ignore his own son as he made himself a cup of tea. 

“Why won’t you tell me?! All I have of mom is a few photos of her! I don’t know anything else- I want to know dad.” The raven haired son continued to interrogate his father, who was still making himself some tea.  
“If you don’t tell me I’m just going to find out myself one way or another!” He slammed his fist on the counter. “Dad TELL ME!” He raised his voice, getting frustrated. 

“Son. I wish there was more to tell you, but there isn’t much. And that is exactly why I don’t want to tell you. You will do everything you can to find out what happened to her.. and I don’t want to risk losing you too.” The professor sighs tiredly, sitting down on the chair by the table, putting his tea down and pulling out his phone.

“Well now I want to know even MORE!” Dib angrily pulls out a chair from the table and sits on the other side. “Dad, I promise I won’t do anything stupid. I’m not as impulsive as I was when I was like- twelve! I’m smarter now!” He huffs, not giving up. 

“ARE YOU SURE ABOUT THAT?!” Gaz yells from the family room, chuckling to herself. 

“YEAH GAZ IM SURE!!” Dib snaps back, turning his attention back to his dad who finally puts his phone down. He turns his phone on the table and slides it over to His son. 

“Your mother was.. a paranormal scientist. She was interested in both science and paranormal activities. She wanted to solve a lot of the paranormal things with science, to try and ‘crack the codes’ as she used to say.” His father said sadly. 

Dib looked at the phone he was handed, looking at a picture of a woman in some kind of lab. It didn’t take long to realise that that woman was his mother.   
“...I thought you didn’t believe in any of that..” His expression fell a little as he looked at the phone, using his two fingers to zoom in on the low quality photo. 

“..I said those things because I didn’t want you to meet the same fate as your mother. I was.. never bothered about the paranormal, but she was very interested. You remind me a lot of her- personality wise.” Membrane’s tone was soft, and quiet. He watched his son look at the photo, feeling conflicted about his decision- but he figured it was time for Dib to know.

“..what do you mean same fate..?” He looked up from the phone, a serious look on his face. 

“..she went missing on one of her paranormal investigations. Her body was never discovered, but the detectives did find blood. In the lab, it was confirmed that it was hers.” The professor said calmly, taking a sip of his tea. 

“Missing? So- you don’t know if she’s dead? She might be alive- what was she investigating? Was she preforming a ritual or going after something? Where is her research?” Dib had too many questions, all of which is father did not seem like he was up for answering. 

“Dib, believe me when I said we searched for months.. all they found was large amounts of blood, and determined that she is.. dead due to how much was there.” He painfully talked about the past, seeming uneasy.   
“All of her paranormal research was taken by authorities and destroyed, even I could not stop that at the time. I have no idea what the investigation was about, but.. last I remember she had been determined to find a creature called mothman.” He looks down at his tea, responding sadly. 

There was a moment of silence as Dib looked at the photo one last time before sliding the phone back across the table to his dad.   
“...how was she like?” Dib decided to push a little further, since who knows when his dad would decide to open up about his mother again. 

“She was.. like you. Very curious, active, determined.. but very loving too. She put aside her paranormal things for a while after you and Gaz were born. She was still however, very passionate about her research and never gave up on it.” The mood seemed to have lighten up when Membrane finished. 

“...I wish I could have gotten to know her.” Dib sighs. “So this whole time, you knew paranormal things were real? And you still made me think I’m crazy and a disappointment-“ He felt his anger riling up again, remembering all those times his dad had made him feel like complete shit for years and years.

“And for that I apologise.. You just reminded me so much of her, it had been difficult to be around.. well, both you and Gaz. You have her spirit, and Gaz has her looks.. Every time you talked about how much you liked paranormal things I just feared that you might end up with the same fate as her. I... did not want to risk losing you to the paranormal as well. Because the paranormal is a huge mystery, no research could explain what could have happened to your mother. It’s something I can not understand, and something I chose not to meddle with.” Membrane looked away, frowning behind the collar of his white lab coat. 

Everything seemed to make more sense for Dib. His dad avoided him and Gaz because they reminded him of their mother. His dad was dismissive and discouraging Dib about the paranormal in an attempt to protect him. But none of this new information could make his past any better- the fact that his dad neglected them and kept discouraging Dib was forever going to be there. And he currently had no idea how to react- but one thing was for sure, he was somewhat glad that he knew more about his mother. 

But he did have one question- 

“So the Florpus- Zim- you know all of that is real and you don’t want to tell the world?” Dib looked at his dad with wide, confused eyes. 

“..I do not want to share something I can not fully understand. This could result in panic, confusion, death and maybe even extinction. It is dangerous to tell the whole world about these things, and I prefer to stay away from the paranormal.” His father then gets up from his chair, holding the now empty tea cup.   
“..I have a meeting soon, but.. now you know.” He goes over to the sink, putting the cup there. “..I wish I knew more, but there isn’t much to go off with. Her research was destroyed by authorities, her brother blamed me for her death and claimed most of her belongings- but I do have a few things of her left.” He turns around to face Dib. 

“..please keep your promise Dib, and don’t do anything dangerous..” 

-End of Flashback- 

He keeps walking through the forest, using his phone as a flash light and now using his physical map- which had been another backup. He pushes through branches and bushes, going past trees and passing by a few deer and raccoons.   
He ties bright yellow ribbons on trees he passes every few steps, taking even more precautions just in case. He had promised his dad he wouldn’t do anything dangerous- and now he was going out in the middle of the night to the place his mother’s blood was found. 

Dib assumed his mother went out to go look for mothman- and if that had been the case, did mothman kill her? The creature wasn't known to be aggressive, but can be territorial when it wants to be.

“This should be the area..” He stops in an opening in the forest, looking around curiously. The moonlight gave him enough light as he walked towards the centre, kneeling down and examining the ground. Of course there was nothing but tall grass since this was 15 years ago, but Dib needed to find something- anything.   
He looks around for a good hour, getting things out of his brief case and using his detectors to try and detect something. He even double checked his map to make sure he was in the right location- and he was. 

He stands up, tapping his chin and looking at his surroundings once again. 

Then a snap of a twig from behind makes him jump, whipping around and grabbing one of the laser guns he had stolen from Zim and modified. He pointed it towards the source of the sound, standing still and his eyes focusing on that area. 

“Who’s there?!” Dib raises his voice, not taking his eyes off of that dark area beyond the trees of the forest. 

There was a low growl, bright blood red eyes glowed in the dark beyond before a black shadow leapt towards Dib. Snarling and glaring it’s sharp teeth as raven feathers swept and engulfed him.   
He panicked, shooting a laser from his gun but only grazing the side of his shoulder. The creature slashed its claws at Dib, who stumbled to the floor and cried out in pain. Those claws were sharp, now covered in Dib’s blood as it shone under the moon light. The human was holding his side were he had deep cuts, blood gushing out and getting his shirt red. 

The creature wasn’t done, showing its sharp razor teeth it growled and loomed above Dib. It howled and moved its head down with its mouth wide open- about to rip out the human’s throat.   
The monster was close enough this time, and Dib couldn’t miss. He shot right into its head, the laser going straight through its brain. The large feathery creature didn’t even make a sound as its heavy body went limp on top of Dib. Now his shirt was stained in both his blood and the creatures blood. 

He cringed, pushing it off of his body and scurrying away. He crawled over to a tree, still on the ground as he sat up and rest back against it whilst breathing heavily.  
“..what is that? A big feathery creature.. are those antenna? .. wings? Holy shit-“ Dib was out of breath as he mumbled to himself. He took his glasses off, wiping the blood against whatever fabric was on him. He put them back on, finally getting a better look at the dead creature. 

“...fuck- was that mothman?! Shit-“ He tried to stand up, but it only made him feel dizzy. He looked down, still losing large amounts of blood. He put his arm tightly over his wound, looking around for his brief case.   
He cursed himself for not being on full alert- of course paranormal hunting at night was always dangerous! Usually Dib was prepared and ready to flee or fight, or maybe even negotiate. But today, he had been too fussed over the mystery regarding his mom. He was too caught up in it, not really thinking and rushing out the house in the dead of night- not even knowing what he was after. The only thing for defence he had was that laser gun- and even then, Dib only brought it with him because he kept it in the car and decided last minute that he should take it with him.

He had never wanted to kill a paranormal creature- never wanted it to come down to this. He was a fan of mothman! He had seen glimpses of him in the forest in the past, but he always ran or flew away or was too far for Dib to see properly. Last he checked, mothman was not hostile and lived in the forest peacefully. Or at least that was what he thought..

“..fuck..” He looks down, feeling cold and his skin getting pale. Blood just continued to flow out of him and soak everything, and his vision was blurring with each second. 

It didn’t take long for him to pass out, eyes closing and going unconscious as his body dropped to the side and lay on the ground. 

——————————————-

He awoke with a ringing in his head, his vision blurry as he grumbled and pushed himself up. For a second, he thought he was dead- but the world was starting to feel too real the more he woke up. Dib blinked, turning his head and looking around, frowning and wondering why everything was blurred so badly. He decided to give his glasses a wipe, and took them off only to quickly realize the world was clear and sharp as could be.

“Whoa..” He set his glasses down beside him, rubbing his eyes and looking at everything in what seemed to be high definition. Sure it was nighttime and rather dark, but Dib could see perfectly fine. It almost felt like he had night vision, on top of 20/20 vision. He shook his head, trying to remember what had happened. The red dried blood on his clothes and body a few feet away was enough to trigger his memory, and so he recalled what he thought would be his final moments. 

“Wait a minute-“ Dib didn’t feel any pain as he moved his hand down to his side. He carefully lifted his red stained shirt up, and saw absolutely nothing. His skin was perfect and as good as new- no deep cuts and no scars either. He was confused at first, but a lone black feather blew over to him which startled him. He was reminded of the cause of that scar, quickly standing up to his feet and looking at the large heap of black feathers on the ground a few feet away from him.  
“Right, I.. killed him.” He frowned, very carefully and slowly approaching what he thought was the dead body of mothman. 

“What the fuck..” He kicked the heap of feathers with his foot, and the feathers all blew away. It wasn’t a body, just a pile of black feathers gathered like a pile of raked leaves. “I’m so confused..” He mumbled to himself, looking down at where the blood was staining his clothes- to where his cut should have been.

The blood was there as well as the rip in his shirt, meaning he was cut. Then where were the said cuts? Where was the beast that gave him the cut? Or was this just another one of those ghosts pranking him? They always loved to mess with him and give him supernatural realistic dreams and confused him. Maybe he fell asleep or hit his head, then the ghosts tore his shirt and put fake blood on him, and gave him that dream?   
The idea was a bit of a stretch, but Dib couldn’t think of any other reason to describe what had happened. It was very late, and even the pile of black feathers seemed to have scattered and retreated into the forest for the night. Dib was suddenly feeling so exhausted, so he picked up his glasses and put them on- forgetting that he could see.

“Oh right-“ He mumbled as the glasses blurred his vision. He held his round glasses, popping the glass out of the frames before setting it back on his face- since he knew he would probably keep putting his glasses on by habit. Plus, it felt weird to not have glasses on, and it made him feel partly naked or something. 

Dib picked up his brief case, deep in thought as he also picked up his cracked phone.   
“3am.. damn.” He mumbled and shoved his phone back in his pocket, and left the scene. As much as he wanted to stay and investigate more, he had school in four or five hours. He needed to get home, go in a shower, throw away his ripped shirt and try to clean his other clothes before his dad found any of it. Plus the smell of blood was really getting to him- usually he didn’t care, but for some reason right now.. the smell was intensified. It felt stronger, and Dib assumed it was because of the large amounts all over him. 

He made it to the car, throwing his brief case in the back as well as his black coat and torn shirt. He’d rather drive shirtless then covered in a bloody shirt. And so he left the scene, deciding that he was too tired to think right now and focused on getting home. He had a test tomorrow, and he swore to himself that he will beat Zim grade wise. He had always been the top student in the class- he was smart, but lacked the patience and restrain to just fight Zim on sight at times. He hated how that alien sneered, smirked and looked at him as if he was above him. Zim always acted like a cat, toying with its prey and being all salty and petty. And while Zim fought mostly with words, Dib could only think of to use his fists at times. 

Zim was by no means weak- he’s tiny, skinny and looks like he could be blown over with a gust of wind. But he was definitely a soldier. He had tactics, ways in combat that he probably learned overtime to defeat Dib. Zim was small, so it was harder to aim at him, and he was also very quick. Not to mention those sharp claws, flexible body and iron grip. His punches and kicks didn’t hurt as much, but it all depended where he punched and kicked. He figured out all too quickly about the male weak spot, and he was so inconveniently close to that area height wise. It doesn’t help that his boots were pointy and he could kick high as well. 

Just thinking about that selfish smirk, the toying tone and that gaze made his blood boil. 

Then a crack was heard, and Dib was holding on to a broken wheel. His grip got too tight, and crushed the steering wheel. He could still drive and steer, but he knew he would be in so much trouble if his Dad or Gaz found out.   
“Fuck!” He cursed as he held onto the wheel, loosening his grip. Sure Zim made him mad, but he never thought that thinking about him would give him this much strength to break the wheel. He never even remembered being this strong, he wasn’t even trying to break the thing. 

He took a deep breath, keeping his hands gently on the crushed steering wheel and kept his eyes on the road. He chose not to think about Zim for now, because he knew that that Irken always brought out the worst in him even when he wasn’t around. 

——————————-

When he got home, the first thing he did was throw away his ruined shirt in the garbage outside. The smell of trash easily overthrew the smell of blood, but for some reason Dib could still smell it- there was some on his jeans and other coat in his arms. That was probably it- and so he took his brief case and walked into his home, glad that Gaz was most likely in her room asleep. He was quick to toss his bloody clothes in the washing and then hop in the shower, sighing of relief when the warm water hit his skin and started to rinse everything away.

He began to recall what had happened today- and it was all just one big mess. He wished everything could make more sense. Why didn’t he find anything? Why did he have that weird Mothman dream? Was it the ghosts pranking him again? Or was it an actual encounter? If so, why was Mothman hostile? Is Mothman even alive, or did he actually kill him?

Dib growled in frustration, grabbing the body soap as he began to scrub his skin.

“OW!” He yelped and moved his hand away, red droplets of blood started dripping onto the white tiled floor. Dib raised his hand, seeming confused as he looked at the blood on his finger tips.   
He rinsed his hand and examined his fingertips closer, realizing that his nails seemed… sharper, more claw-like than before. They seemed longer, and were more pointed near the ends and maybe even darker in color. His eyes then moved down to examine the cut on his arm, but there was none. 

“..What the.. huh?” He rubbed the perfect skin, not seeing a cut and confused as to where the blood came from.  
“..Ether the ghosts put some curse on me, or I’m just really tired..” He mumbled to himself, and this time gently scrubbed his body with his palm before moving on to washing his hair.

He got ready for bed, putting his pajamas on and finding them oddly tight- these were pretty old pajamas anyway. He got cozy in bed, putting his glassless on the bedside table before going under the covers. He closed his eyes, and in a second all of his tiredness seemed to have faded. He didn’t feel the least bit sleepy- and if anything, he felt more energized and awake. It didn’t help that his blankets also seemed to smell very weird- not bad, but just a very strong scent of something he couldn’t pin point. 

He tried to sleep the best he could, thinking it must just be his insomnia. He rolled around on his bed, trying to get in a comfortable position to fall asleep. He tried to listen to music, put the fan on, and even change pajamas but nothing was working. He also tried walking around the house, doing a few pushups in an attempt to tire his body out. But yet again, it didn’t work- and the pushups seemed much easier than they normal would have been. Usually Dib would do about ten pushups and be done- but today, he did twenty and didn’t feel anything. 

“Urgh- what else..” He sighed, flopping back on the bed and staring up at the ceiling. He tried to think of other things he could do to tire himself out, and the only thing he could think of at the time was jerking himself off. So he quickly reached for his phone resting on his bed side table, lifting it up and going on to the usual porn site on his private browser.   
He scrolls around, trying to find something interesting but finding nothing. He didn’t do this often- maybe in his earlier years of Hi Skool. But now it didn’t so much as interest him, nor did he have the time to do it anymore. He very much preferred chasing Zim and making sure the world doesn’t end than jerking off to some pixels on a screen. It always took a good few minutes for him to even find a video that he might be able to get off to. He was bisexual after all, and all the memes on the internet would say that he should have more than enough options.

He eventually found a good POV video of a guy fucking some random woman. He didn’t really enjoy the moans- they all sounded so fake, and increased the risk of being caught in his house with such thin walls anyway. Sure he could put on headphones, but the moans usually just made him cringe and stop him from being aroused. He had no interest in listening to some man or woman moaning each other's name. And again- he was very picky. Not a lot could turn him on, because there weren’t many things that interested him in the sex field. Yes he had those Hi Skool crushes that he might have jerked off to, and maybe he got a blowjob once, but as of now he didn’t have a crush on anyone. He had more important things to do than to be simping for a random human that won’t believe anything he says and will think he’s crazy. 

But there has always been one thing- one being- that always interested him. He always brushed it off as being curious because he was a paranormal creature and because he wanted to just discover everything there was to know about him. He was an alien! How could he not be curious about him? Dib refused to believe even the slightest that he might be sexually and romantically attracted to that little shit called Zim. He’s his enemy, and Dib plans on keeping it that way. 

He shook his head and got the Irken out of his thoughts as he focused on the video. Shoving his hand under the waistband of his pants and boxers, he grabbed his limp dick and pulled it out of its confines.   
He played the video, and slowly started to pump his hand up and down as he watched with a bored expression. He watched the video for a while, speeding up his stroking when the guy went faster and slowing when he went slower. And about half way through the video, Dib was hard- but not as hard as he would have liked to be. 

Frustrated, he put the phone down and sighed. Now he was just half erect and unsatisfied and it was the most annoying thing in the world. 

Regardless he continued to pump his dick, moving his hand up and down and trying to use his imagination to come up with something. 

And of course, his mind went straight to Zim. 

He imagined him bending the Irken over on the ground and pulling up that stupid pink dress. Yanking his black leggings down and whatever alien boxers he wore underneath. He imagined some alien dick in between his legs, maybe a tentacle or an ovipositor of some sorts. Zim was already hard, his alien dick Dib imagined to be on the bigger side, maybe curling around or just hard like a human. He would move his hand to Zim’s front to give him a good few pumps of his alien dick- the little Irken would moan and cry out his name and buck into his hand. 

Dib imagined himself retracting his hand and positioning his dick right by the alien’s ass. Spreading those cheeks and pushing his tip in before sliding all the way up inside. He would give it a few good slaps before grabbing those suspiciously wide hips and pick up a pace.   
The alien’s small body beneath him would move back and fourth with his thrusts, his antenna bouncing and ass cheeks slapping against his skin. He imagined Zim to be the tightest thing in the world- he was so small, probably a little over a quarter of Dib’s height. Maybe with his antenna he would make it to half his height- but the point was, he hadn’t grown or changed at all since day one on Earth. 

“How do you like that you alien scum! How can you destroy Earth when I’m destroying you?!” Dib imagined himself saying as he picked up the pace, pumping his hand faster.   
He didn’t realise him self growling, moving his hips up and thrusting into his hand as he pumped. He couldn’t remember the last time he was turned on this much- he peeked an eye open and saw his dick, fully erect and bright red at the tip. Veins bulging and precum dripping all over the place in large amounts- was his dick always this big? 

He couldn’t remember the last time he was even erect, so maybe when he was hard he was this big. Who knows- but he knew he was at least nine inches by the looks of it. The human found himself blushing at the realisation, because last he checked he thought he had been six inches when hard. 

Either way, he closed his eyes again and imagined, moaning as he fucked the alien’s tight ass. Zim would be crying out for mercy, surrendering and saying that he gives up on Earth. Saying that Dib wins and then eventually begging him to fuck him harder.   
He moved his hand as fast as he could up and down his dick, breathing heavily and bed squeaking a little as he moved his hips up into his hand. 

“Fuuuckkk Zimmmm-!”

He drooled, his vision going hazy as he moaned. His body buzzed, his legs began to shake as he got closer and closer. He imagined some weird substance shooting out of Zim’s dick as his insides tightens, and that did it for him. He threw his head back and growled loudly, thrusting into his hand one last time before cumming hard. 

He cried of pleasure and trembled, feeling load after load shoot out of his twitching swollen dick in large amounts. He didn’t even realise the low growl rumbling from his chest, which definitely sounded inhuman. Too lost in pleasure, he kept thinking about filling up Zim’s ass with his cum. Pulling out only to watch as a waterfall of white cum gush out of his hole. Dripping down the crevice and pooling between his legs. 

Dib was out of breath by the time he finished, feeling extremely tired from cumming for what felt like a straight ten minutes.   
He opened his half lidded eyes, which quickly widened when he saw the mess he made. He sat up, moving his hand away and seeming confused as he looked at his legs, his torso, his bed, and the floor. 

“..what the fuck..”

White cum was literally everywhere- too much of it. Loads stained his bed, his own pants, his chest, and some shot all the way up and onto the floor. It was like someone splattered a whole bucket of cum on his bed. There was no way a human could produce this much- this was the amount of a horse. Or some big animal- he didn’t know. 

The worst part? Dib could go another round. He should be tired, exhausted and completely wasted from just cumming once. Especially with this amount, but he felt like he could go again.   
A part of him wanted to believe it was Zim’s fault- Zim did this to him. He made him cum like a monster, which should have been a good thing if Dib hadn’t been his enemy or actually have feelings for him. 

The human never realised how well he could see in the dark that night. He didn’t notice the little feathers on his bed, and he didn’t notice the bumps on his forehead as he finished cleaning up the cum and decided to sleep on the couch downstairs.


End file.
